1. Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
2. Department of Orthopedic Surgery, Brigham and Woman’s Hospital, Boston, Massachusetts
3. Department of Orthopedic Surgery, Rothman Orthopedic Institute at Thomas Jefferson University Hospital, Philadelphia, Pennsylvania
4. Department of Orthopaedic Surgery, Medstar Orthopaedic Institute, Georgetown University School of Medicine, Washington, DC